Dystonia is a debilitating hyperkinetic movement disorder, which can be transmitted as a monogenic trait. Here, we describe homozygous frameshift, nonsense and missense variants in TSPOAP1, encoding the active zone RIM-binding protein 1 (RIMBP1), as a novel genetic cause of autosomal recessive dystonia in seven subjects from three unrelated families. Subjects carrying loss-of-function variants presented with juvenile-onset progressive generalized dystonia, associated with intellectual disability and cerebellar atrophy. Conversely, subjects carrying a pathogenic missense variant (p.Gly1808Ser) presented with isolated adult-onset focal dystonia. In mice, complete loss of RIMBP1, known to reduce neurotransmission, led to motor abnormalities reminiscent of dystonia, decreased Purkinje cell dendritic arborization, and reduced numbers of cerebellar synapses. In vitro analysis of the p.Gly1808Ser variant showed larger spike-evoked calcium transients and enhanced neurotransmission, suggesting that RIMBP1-linked dystonia can be caused by either reduced or enhanced rates of spike-evoked release in relevant neural networks. Our findings establish a direct link between dysfunction of the presynaptic active zone and dystonia and highlight the critical role played by well-balanced neurotransmission in motor control and disease pathogenesis.
Niccolò E. Mencacci, Marisa M. Brockmann, Jinye Dai, Sander Pajusalu, Burcu Atasu, Joaquin Campos, Gabriela Pino, Paulina Gonzalez-Latapi, Christopher Patzke, Michael Schwake, Arianna Tucci, Alan Pittman, Javier Simon-Sanchez, Gemma L. Carvill, Bettina Balint, Sarah Wiethoff, Thomas T. Warner, Apostolos Papandreou, Audrey Ker Shin Soo, Reet Rein, Liis Kadastik-Eerme, Sanna Puusepp, Karit Reinson, Tiiu Tomberg, Hasmet Hanagasi, Thomas Gasser, Kailash P. Bhatia, Manju A. Kurian, Ebba Lohmann, Katrin Õunap, Christian Rosenmund, Thomas Südhof, Nicholas Wood, Dimitri Krainc, Claudio Acuna
In inherited neurodevelopmental diseases, pathogenic processes unique to critical periods during early brain development may preclude effectiveness of gene modification therapies applied later in life. We explored this question in a mouse model of DYT1 dystonia, a neurodevelopmental disease caused by a loss-of-function mutation in the TOR1A gene encoding torsinA. To define the temporal requirements for torsinA in normal motor function and gene replacement therapy, we developed a mouse line enabling spatiotemporal control of the endogenous torsinA allele. Suppressing torsinA during embryogenesis caused dystonia-mimicking behavioral and neuropathological phenotypes. Suppressing torsinA during adulthood, however, elicited no discernible abnormalities, establishing an essential requirement for torsinA during a developmental critical period. The developing CNS exhibited a parallel “therapeutic critical period” for torsinA repletion. While restoring torsinA in juvenile DYT1 mice rescued motor phenotypes, there was no benefit from adult torsinA repletion. These data establish a unique requirement for torsinA in the developing nervous system and demonstrate that the critical period genetic insult provokes permanent pathophysiology mechanistically delinked from torsinA function. These findings imply that to be effective, torsinA-based therapeutic strategies must be employed early in the course of DYT1 dystonia.
Jay Li, Daniel S. Levin, Audrey J. Kim, Samuel S. Pappas, William T. Dauer
Leber’s hereditary optic neuropathy (LHON) is the most frequent mitochondrial disease and was the first to be genetically defined by a point mutation in the mitochondrial DNA (mtDNA). A molecular diagnosis is reached in up to 95%, the vast majority of which are accounted for by three mutations within mitochondrial complex I (CI) subunit encoding genes in the mtDNA (mtLHON). Here, we resolve the enigma of LHON in the absence of pathogenic mtDNA mutations. We describe biallelic mutations in a nuclear encoded gene, DNAJC30, in 33 unsolved patients from 29 families and establish an autosomal recessive mode of inheritance for LHON (arLHON), which to date has been a prime example of a maternally inherited disorder. Remarkably, all hallmarks of mtLHON are recapitulated, including incomplete penetrance, male predominance, and significant idebenone responsivity. Moreover, by tracking protein turnover in patient-derived cell lines and a DNAJC30-knock-out cellular model, we measure reduced turnover of specific CI N-module subunits and a resultant impairment of CI function. This demonstrates DNAJC30 is to be a chaperone protein needed for the efficient exchange of CI subunits exposed to reactive oxygen species and integral to a mitochondrial CI repair mechanism, thereby providing the first example of a disease resulting from impaired exchange of assembled respiratory chain subunits.
Sarah L. Stenton, Natalia L. Sheremet, Claudia B. Catarino, Natalia Andreeva, Zahra Assouline, Piero Barboni, Ortal Barel, Riccardo Berutti, Igor O. Bychkov, Leonardo Caporali, Mariantonietta Capristo, Michele Carbonelli, Maria Lucia Cascavilla, Peter Charbel Issa, Peter Freisinger, Sylvie Gerber, Daniele Ghezzi, Elisabeth Graf, Juliana Heidler, Maja Hempel, Elise Heon, Yulia S. Itkis, Elisheva Javasky, Josseline Kaplan, Robert Kopajtich, Cornelia Kornblum, Reka Kovacs-Nagy, Tatiana Krylova, Wolfram S. Kunz, Chiara La Morgia, Costanza Lamperti, Christina Ludwig, Pedro F. Malacarne, Alessandra Maresca, Johannes A. Mayr, Jana Meisterknecht, Tatiana Nevinitsyna, Flavia Palombo, Ben Pode-Shakked, Maria S. Shmelkova, Tim M. Strom, Francesca Tagliavini, Michal Tzadok, Amelie T. van der Ven, Catherine Vignal-Clermont, Matias Wagner, Ekaterina Zakharova, Nino Zhorzholadze, Jen-Michel Rozet, Valerio Carelli, Polina Tsygankova, Thomas Klopstock, Ilka Wittig, Holger Prokisch
Gene editing holds the potential to correct mutations and cure devastating genetic disorders. The technology has not yet proven efficacious for therapeutic use in central nervous system (CNS) diseases with ubiquitous neuronal defects. Angelman syndrome (AS), a severe neurodevelopmental disorder, is caused by a lack of maternal expression of the UBE3A gene. Due to genomic imprinting, only neurons are affected. One therapeutic approach focuses on the intact paternal UBE3A copy in AS patients that is silenced by an antisense transcript (UBE3A-ATS). We show here that gene editing of Ube3a-ATS in the mouse brain results in the formation of base pair insertions/deletions (indels) in neurons and the subsequent unsilencing of the paternal Ube3a allele in neurons, which partially corrects the behavior phenotype of a murine AS model. This study provides compelling evidence to further investigate editing of the homologous region of the human UBE3A-ATS, since this may provide a lasting therapeutic effect for AS patients.
Ralf S. Schmid, Xuefeng Deng, Priyalakshmi Panikker, Msema Msackyi, Camilo Breton, James M. Wilson
Mutant isocitrate-dehydrogenase-1 (IDH1-R132H; mIDH1) is a hallmark of adult gliomas. Lower grade mIDH1 gliomas are classified into two molecular subgroups: (i) 1p/19q co-deletion/TERT-promoter mutations or (ii) inactivating mutations in α-thalassemia/mental retardation syndrome X-linked (ATRX) and TP53. This work, focuses on gliomas’ subtype harboring mIDH1, TP53 and ATRX inactivation. IDH1-R132H is a gain-of-function mutation that converts α-ketoglutarate into 2-hydroxyglutarate (D-2HG). The role of D-2HG within the tumor microenvironment of mIDH1/mATRX/mTP53 gliomas remains unexplored. Inhibition of D-2HG, when used as monotherapy or in combination with radiation and temozolomide (IR/TMZ), led to increased median survival (MS) of mIDH1 glioma bearing mice. Also, D-2HG inhibition elicited anti-mIDH1 glioma immunological memory. In response to D-2HG inhibition, PD-L1 expression levels on mIDH1-glioma cells increased to similar levels as observed in wild-type-IDH1 gliomas. Thus, we combined D-2HG inhibition/IR/TMZ with anti-PDL1 immune checkpoint-blockade and observed complete tumor regression in 60% of mIDH1 glioma bearing mice. This combination strategy reduced T-cell exhaustion and favored the generation of memory CD8+ T-cells. Our findings demonstrate that metabolic reprogramming elicits anti-mIDH1 glioma immunity, leading to increased MS and immunological memory. Our preclinical data supports the testing of IDH-R132H inhibitors in combination with IR/TMZ and anti-PDL1 as targeted therapy for mIDH1/mATRX/mTP53 glioma patients.
Padma Kadiyala, Stephen V. Carney, Jessica C. Gauss, Maria B. Garcia-Fabiani, Santiago Haase, Mahmoud S. Alghamri, Felipe J. Núñez, Yayuan Liu, Minzhi Yu, Ayman W. Taher, Fernando M. Nunez, Dan Li, Marta B. Edwards, Celina G. Kleer, Henry Appelman, Yilun Sun, Lili Zhao, James J. Moon, Anna Schwendeman, Pedro R. Lowenstein, Maria G. Castro
Intellectual and social disabilities are common comorbidities in adolescents and adults with MAGEL2 gene deficiency characterizing the Prader-Willi and Schaaf-Yang neurodevelopmental syndromes. The cellular and molecular mechanisms underlying the risk for autism in these syndromes are not understood. We ask whether vasopressin functions are altered by MAGEL2 deficiency and whether a treatment with vasopressin can alleviate the disabilities of social behavior. We used Magel2 knockout mice (adult males) combined with optogenetic or pharmacological tools to characterize disease modifications in the vasopressinergic brain system and monitor its impact on neurophysiological and behavioral functions. We find that the activation of vasopressin neurons and its projections in the lateral septum are inappropriate to perform a social habituation/discrimination task. Mechanistically, the lack of vasopressin impedes the deactivation of somatostatin neurons in the lateral septum, which predicts social discrimination deficits. Correction of vasopressin septal content by administration or optogenetic stimulation of projecting axons suppressed the activity of somatostatin neurons and ameliorated social behavior. This preclinical study identifies vasopressin in the lateral septum as a key factor in the pathophysiology.
Amélie M. Borie, Yann Dromard, Gilles Guillon, Aleksandra Olma, Maurice Manning, Françoise Muscatelli, Michel G. Desarmenien, Freddy Jeanneteau
Polyglutamine (polyQ) diseases are devastating, slowly progressing neurodegenerative conditions caused by expansion of polyQ-encoding CAG repeats within the coding regions of distinct, unrelated genes. In spinal and bulbar muscular atrophy (SBMA), polyQ expansion within the androgen receptor (AR) causes progressive neuromuscular toxicity, the molecular basis of which is unclear. Using quantitative proteomics, we identified changes in the AR interactome caused by polyQ expansion. We found that the deubiquitinase USP7 preferentially interacts with polyQ-expanded AR, and that lowering USP7 levels reduced mutant AR aggregation and cytotoxicity in cell models of SBMA. Moreover, USP7 knockdown suppressed disease phenotypes in SBMA and spinocerebellar ataxia type 3 (SCA3) fly models, and monoallelic knockout of Usp7 ameliorated several motor deficiencies in transgenic SBMA mice. USP7 overexpression resulted in reduced AR ubiquitination, indicating the direct action of USP7 on AR. Using quantitative proteomics, we identified the ubiquitinated lysine residues on mutant AR that are regulated by USP7. Finally, we found that USP7 also differentially interacts with mutant Huntingtin (HTT) protein in striatum and frontal cortex of a knock-in mouse model of Huntington’s disease. Taken together, our findings reveal a critical role for USP7 in the pathophysiology of SBMA and suggest a similar role in SCA3 and Huntington’s disease.
Anna Pluciennik, Yuhong Liu, Elana Molotsky, Gregory B. Marsh, Bedri Ranxhi, Frederick J. Arnold, Sophie St-Cyr, Beverly L. Davidson, Naemeh Pourshafie, Andrew P. Lieberman, Wei Gu, Sokol V. Todi, Diane E Merry
Dysregulation of habit formation has been recently proposed as pivotal to eating disorders. Here, we report that a subset of patients suffering from restrictive anorexia nervosa have enhanced habit formation compared with healthy controls. Habit formation is modulated by striatal cholinergic interneurons. These interneurons express vesicular transporters for acetylcholine (VAChT) and glutamate (VGLUT3) and use acetylcholine/glutamate cotransmission to regulate striatal functions. Using mice with genetically silenced VAChT (VAChT conditional KO, VAChTcKO) or VGLUT3 (VGLUT3cKO), we investigated the roles that acetylcholine and glutamate released by cholinergic interneurons play in habit formation and maladaptive eating. Silencing glutamate favored goal-directed behaviors and had no impact on eating behavior. In contrast, VAChTcKO mice were more prone to habits and maladaptive eating. Specific deletion of VAChT in the dorsomedial striatum of adult mice was sufficient to phenocopy maladaptive eating behaviors of VAChTcKO mice. Interestingly, VAChTcKO mice had reduced dopamine release in the dorsomedial striatum but not in the dorsolateral striatum. The dysfunctional eating behavior of VAChTcKO mice was alleviated by donepezil and by l-DOPA, confirming an acetylcholine/dopamine deficit. Our study reveals that loss of acetylcholine leads to a dopamine imbalance in striatal compartments, thereby promoting habits and vulnerability to maladaptive eating in mice.
Mathieu Favier, Helena Janickova, Damian Justo, Ornela Kljakic, Léonie Runtz, Joman Y. Natsheh, Tharick A. Pascoal, Jurgen Germann, Daniel Gallino, Jun-II Kang, Xiang Qi Meng, Christina Antinora, Sanda Raulic, Jacob P.R. Jacobsen, Luc Moquin, Erika Vigneault, Alain Gratton, Marc G. Caron, Philibert Duriez, Mark P. Brandon, Pedro Rosa Neto, M. Mallar Chakravarty, Mohammad M. Herzallah, Philip Gorwood, Marco A.M. Prado, Vania F. Prado, Salah El Mestikawy
Oligodendrocytes express low-density lipoprotein receptor (LDLR) to endocytose cholesterol for the maintenance of adulthood myelination. However, the potential role of LDLR in chronic cerebral ischemia-related demyelination remains unclear. We used bilateral carotid artery stenosis (BCAS) to induce sustained cerebral ischemia in mice. This hypoxic-ischemic injury caused a remarkable decline of oligodendroglial LDLR with impaired oligodendroglial differentiation and survival. Oligodendroglial cholesterol levels, however, remained unchanged. Mice miR-344e-3p and human homolog miR-410-3p, two miRNAs directly targeting Ldlr, were identified in experimental and clinical leukoaraiosis, thus leading to LDLR reduction. Lentiviral delivery of LDLR ameliorated the demyelination following chronic cerebral ischemia. By contrast, Ldlr-/- mice displayed inadequate myelination in the corpus callosum. Ldlr-/- oligodendrocyte progenitor cells (OPCs) exhibited defective ability to differentiate and myelinate axons in vitro. Transplantation with Ldlr-/- OPCs could not rescue the BCAS-induced demyelination. Such LDLR-dependent myelin restoration might involve a physical interaction of the Asn-Pro-Val-Tyr (NPVY) motif with phosphotyrosine binding domain of Shc, which subsequently activated MEK/ERK pathway. Together, our findings demonstrate that the aberrant oligodendroglial LDLR in chronic cerebral ischemia impairs myelination through intracellular signal transduction. Preservation of oligodendroglial LDLR may provide a promising approach to treat ischemic demyelination.
Yi Xie, Xiaohao Zhang, Pengfei Xu, Nana Zhao, Ying Zhao, Yunzi Li, Ye Hong, Mengna Peng, Kang Yuan, Ting Wan, Rui Sun, Deyan Chen, Lili Xu, Jingjing Chen, Hongquan Guo, Wanying Shan, Juanji Li, Rongrong Li, Yunyun Xiong, Dezhi Liu, Yuhui Wang, George Liu, Ruidong Ye, Xinfeng Liu
Matrix metalloproteinases (MMPs) are synthesized by neurons and glia and released into the extracellular space, where they act as modulators of neuroplasticity and neuroinflammatory agents. Development of epilepsy (epileptogenesis) is associated with increased expression of MMPs and therefore they may represent potential therapeutic drug targets. Using qPCR and immunohistochemistry, we studied the expression of MMPs and their endogenous inhibitors TIMPs, in patients with status epilepticus (SE) or temporal lobe epilepsy (TLE), and in a rat TLE model. Furthermore, we tested the MMP2/9 inhibitor IPR-179 in the rapid kindling rat model and in the intrahippocampal kainic-acid mouse model.In both human and experimental epilepsy, MMP and TIMP expression was persistently dysregulated in the hippocampus compared to controls. IPR-179 treatment reduced seizure severity in the rapid kindling model and reduced the number of spontaneous seizures in the kainic-acid model (during and up to 7 weeks after delivery) without side effects while improving cognitive behavior. Moreover, our data suggest that IPR-179 prevented an MMP2/9-dependent switch-off normally restraining network excitability during the activity period. Since increased MMP expression is a prominent hallmark of the human epileptogenic brain and the MMP inhibitor IPR-179 has antiseizure and antiepileptogenic effects in rodent epilepsy models and attenuates seizure-induced cognitive decline, it deserves further investigation in clinical trials.
Diede W.M. Broekaart, Alexandra Bertran, Shaobo Jia, Anatoly Korotkov, Oleg Senkov, Anika Bongaarts, James D. Mills, Jasper Joris Anink, Jesus Seco-Moral, Johannes Baaijen, Sander Idema, Elodie Chabrol, Albert Becker, Wytse Wadman, Teresa Tarrago, Jan A. Gorter, Eleonora Aronica, Roger Prades, Alexander Dityatev, Erwin A. van Vliet